Frequently asked questions (FAQs)

1. What is a typical, suitable proximate analysis for the diet for roho labeo?

2. What is a typical feed formulation for roho labeo diets?

Feed formulae of commonly used and suggested formulated feeds for different life stages of roho labeo:

*Mixture of tapioca flour, wheat flour and rice flour in 6:3:1 ratio

3. What plant protein sources and typical inclusion rates can I consider for roho labeo feeds?

The following plant protein sources have been used in rohu diets: soybean meal (<50 percent); grass pea, Lathyrus sativus (<30 percent); mustard oil cake (<35 percent); canola (rapeseed) (<30 percent); sesame meal, raw (<20 percent) and fermented (<40 percent); linseed meal, raw (<20 percent) and fermented (<40 percent); copra meal (<20 percent); coconut oil cake (<40 percent); groundnut cake (<25 percent); cottonseed cake; black and green gram husk; sunflower oil cake; salseed cake; Azolla meal; corn gluten meal (<6 percent). Plant products with protein levels under 20 percent that are used in rohu diets include: rice bran (<50 percent); rice polishing (<29 percent); polished and broken rice (6–13 percent); wheat bran (9–14 percent); wheat flour (<26 percent); maize meal (<25 percent); tapioca flour.

Recommended levels of some alternative protein sources for roho labeo:

4. What oils are suitable for inclusion for roho labeo diets?

Corn (maize) oil, soybean oil, sunflower oil, coconut oil, olive oil, linseed oil and peanut oil have all been used in rohu diets. Soybean oil is most frequently used in rohu diet.

5. What vitamin and mineral mixture can I use in my pelleted feed for roho labeo?

Except for vitamin A, C and E, little is known about the vitamin requirements of rohu. Under semi-intensive polyculture conditions, it has been reported that there is no added benefit by adding supplementary vitamins to the feed. However, under laboratory conditions the optimum requirements of rohu fry for vitamins A, C and E have been reported to be 2000 IU/kg, 1409 µg/g and 132 mg/kg dry diet, respectively. Regarding mineral requirements, except for calcium and phosphorus, there is no information on the mineral requirement of rohu. It has been reported that the optimum calcium and phosphorus requirement of rohu fry are 0.19 and 0.75 percent of the diet, respectively.

6. What size of feed do I need for the different sizes of fish from first-feeding fry onwards and how frequently should I feed my fish?

The below feeding table for rohu it is based on pond culture condition:

7. Is my farming intensity considered extensive, semi-intensive or intensive?

In general, rohu farming is not defined in this way. For grow-out, fingerlings are stocked at a density of 5 000–10 000/ha and sometimes a rate of 15 000/ha in polyculture systems, in which rohu comprise between 15-60 percent of the pond population. The fish are reared for a period of 10–12 months and reach a size of about 700–800 grams. In well prepared ponds, rohu attain 700–1 000g in the first year, 800–2 000g in the second year and 2 000–4 000g in the third year.

8. What yields of rohu are possible if I only apply fertilizers and do not use supplemental feeds?

Typical production from extensive farming involves fertilization as the input and achieving production levels of 1–2 tonnes/ha/year. Fish production levels of 5 000 kg/ha can be achieved without supplementary feeding, only by providing substrata for periphyton that is equivalent to the pond surface area and fertilizing with cow manure at 4 500 kg/ha, urea at 150 kg/ha and triple super phosphate at 150 kg/ha. Adding periphyton substrata equivalent (e.g. bamboo poles) increases fish production. Polyculture systems can achieve up to 7 000 kg/ha over 8 months.

9. What organic fertilizers can I use in my pond?

Practically, any organic material can be used as a fertilizer. Look for what animal manures are locally available and cheap. Poultry, pig and duck manures have relatively high phosphate and nitrogen contents and are good organic fertilizers. Make sure the manure has not been sprayed with insecticides. Raw cow dung is often applied at a rate of 4 000–6 000 kg/ha, two weeks before stocking. If poultry manure is used it is applied at a 3^rd of the cow dung dose.